Editor's note: This is part of a series highlighting the 2021 Olympic Games with a specific emphasis on health and wellness.
July 21, 2021 -- Swimmers need thousands of calories a day. But those calories are different from what a weightlifter needs, and those calories are quite different from what a gymnast or track and field star needs.
With the delayed 2020 Olympics starting this week, we break down the unique – and sometimes startling -- dietary needs of different kinds of elite athletes.
The most decorated Olympian in history, Michael Phelps, debunked the infamous claim that he ate 12,000 calories a day when training for the Olympics. But the actual number was not far from that. Phelps said that he ate between 8,000 and 10,000 calories a day.
While that may seem like a lot, that number is normal for many elite swimmers, according to Allison Mankowski, a board-certified specialist in sports dietetics and a sports dietitian at Eastern Michigan University.
Swimming is one of three sports that burn the most calories, falling right behind running and cycling. Depending on your weight and other physical factors, the butterfly stroke can burn between 660 and 976 calories per hour, according to Livestrong.
“The average male swimmer will probably need at least 5,000 calories a day and potentially up to 10,000 for more intense training periods or larger athletes,” Mankowski says. “Female swimmers will be slightly less but will most likely still need at least 4,000 calories and potentially up to 6,000 or more.”
But these numbers can vary.
“Carbohydrates will make up usually around 55% to 60% of daily intake, with fat around 20% to 25%, and protein around 15% to 25%,” says Mankowski.
- Breakfast: Banana before training; egg omelet with spinach, mushrooms, onion, and salmon
- Yogurt and granola with berries after training
- Lunch: Veggies, lean protein like chicken or salmon, and a carb, such as rice, quinoa, or lentils
- Dinner: Very similar to lunch, but a larger portion, to refuel after a long day of training
Track and Field
Olympic runners have different dietary needs, based on their event.
Long-distance runners need a similar amount of calories as swimmers, with men needing an average of 5,000 to 10,000 or more and females between 4,000 and 6,000 or more, according to Mankowski.
Marathon runners eat a high-carb diet, particularly during training sessions leading up to the race, and on the day of the race, to make sure that they have enough energy to keep them going for long distances.
This is a practice known as carb-loading. You eat a higher percentage of carbohydrates 3 days before a race and then a normal portion the night before.
Carb-loading is often mistaken as eating a ginormous plate of pasta the day before an event, which can lead to bloating and poor performance. Instead, many elite athletes drink carb-rich smoothies or drinks.
Sprinters, on the other hand, need shorts bursts of power instead of energy to last long distances. They require slightly fewer calories than long-distance runners, says Mankowski.
She also says it is important to keep fueling up throughout the day.
“These athletes will need to be eating frequently to make sure they can get in all of the calories they need to perform,” Mankowski says. “Often, this means eating every 2 hours or so, and refueling during longer workouts.”
If this seems low in comparison to other Olympic sports, it may be because gymnastics, an aesthetic sport, burns much fewer calories than an endurance sport like swimming.
For 30 minutes of gymnastics, you can burn around 120 to 168 calories, depending on your weight, according to Harvard Health Publishing. But a sport like running burns between 240 and 671 calories, depending on your weight and the speed of your run.
A study in the Journal of the International Society of Sports Nutritiondefines aesthetic sports as “those which require well-developed physical capacities (power, speed, endurance, flexibility) as well as technical skill and artistry. In such sports, elite performers typically exhibit a low-fat mass, and/or a low body weight.”
Gymnasts can often be expected to follow a stricter diet, compared to athletes in other sports. But different forms of gymnastics have different dietary needs.
For example, in power tumbling, building muscle, speed, power, and endurance are major priorities and can require more energy in the form of calories.
But rhythmic gymnastics is centered on aesthetics, flexibility, and agility. These gymnasts tend to focus on having a small frame, and they eat small meals throughout the day.
Women’s gymnastics, aerobics, and acrobatics usually fall somewhere in the middle and require a balance.
Many Olympic gymnasts start training at a young age. This can cause delayed growth and development and is often cited as the reason why elite gymnasts tend to be shorter and smaller than their peers.
“In many cases, our puberty is delayed due to the physicality required for training and the limited calorie intake,” says Dominique Dawes, a three-time Olympic gymnast and Olympic gold medalist. “As you can imagine, we are burning an enormous amount of energy, but we do not consume a great amount of calories.”
“Gymnasts strive to stay fueled throughout the day,” Dawes says. “It is not uncommon to snack on high-protein foods to sustain the long training sessions.”
While the sport of weightlifting doesn’t burn a significant amount of calories when compared to some Olympic sports, athletes still eat high-calorie diets in order to build muscle mass.
On average, an intense 30-minute weightlifting session burns between 180 and 252 calories, depending on an athlete’s weight, according to Harvard Health Publishing.
Meagan Nielsen, a board-certified specialist in sports dietetics and team dietitian for USA Weightlifting, says the number of calories a weightlifter eats depends on things like their weight goals, current body weight, body composition -- the amount fat, bone and muscle in your body -- and training plan.
“Our smallest weightlifters might consume around 1,800 a day, depending on where they are in regard to competition day,” Nielsen says. “Larger weightlifters, or even those trying to gain weight, can consume between 4,000 and 5,000 calories a day.”
Nielsen says energy from carbohydrates is key for weightlifters in helping both performance and recovery, along with proteins and fats.
“Protein is important to build and maintain the muscle mass that the athletes utilize in resistance training,” she says. “Healthy fats are also important to maintain their hormonal health, protect their bodies as they move heavy weight, and keep their brains and hearts healthy.”
Nielsen says that staying hydrated is also essential, given that dehydration can lead to decreased reaction time and cardiovascular strain.
“Her thing is commonsense food choices, staying hydrated, doing things you need to do to rehab, and eating whole foods,” he says.